Merge tag 'mm-nonmm-stable-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull delay-accounting update from Andrew Morton:
 "A single featurette for delay accounting.

  Delayed a bit because, unusually, it had dependencies on both the
  mm-stable and mm-nonmm-stable queues"

* tag 'mm-nonmm-stable-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  delayacct: track delays from write-protect copy

2 files changed, 33 insertions, 1 deletions

diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
index 6b16a6930a19..58aea2d7385c 100644
--- a/include/linux/delayacct.h
+++ b/include/linux/delayacct.h
@@ -45,9 +45,13 @@ struct task_delay_info {
 	u64 compact_start;
 	u64 compact_delay;	/* wait for memory compact */
 
+	u64 wpcopy_start;
+	u64 wpcopy_delay;	/* wait for write-protect copy */
+
 	u32 freepages_count;	/* total count of memory reclaim */
 	u32 thrashing_count;	/* total count of thrash waits */
 	u32 compact_count;	/* total count of memory compact */
+	u32 wpcopy_count;	/* total count of write-protect copy */
 };
 #endif
 
@@ -75,6 +79,8 @@ extern void __delayacct_swapin_start(void);
 extern void __delayacct_swapin_end(void);
 extern void __delayacct_compact_start(void);
 extern void __delayacct_compact_end(void);
+extern void __delayacct_wpcopy_start(void);
+extern void __delayacct_wpcopy_end(void);
 
 static inline void delayacct_tsk_init(struct task_struct *tsk)
 {
@@ -191,6 +197,24 @@ static inline void delayacct_compact_end(void)
 		__delayacct_compact_end();
 }
 
+static inline void delayacct_wpcopy_start(void)
+{
+	if (!static_branch_unlikely(&delayacct_key))
+		return;
+
+	if (current->delays)
+		__delayacct_wpcopy_start();
+}
+
+static inline void delayacct_wpcopy_end(void)
+{
+	if (!static_branch_unlikely(&delayacct_key))
+		return;
+
+	if (current->delays)
+		__delayacct_wpcopy_end();
+}
+
 #else
 static inline void delayacct_init(void)
 {}
@@ -225,6 +249,10 @@ static inline void delayacct_compact_start(void)
 {}
 static inline void delayacct_compact_end(void)
 {}
+static inline void delayacct_wpcopy_start(void)
+{}
+static inline void delayacct_wpcopy_end(void)
+{}
 
 #endif /* CONFIG_TASK_DELAY_ACCT */
 
diff --git a/include/uapi/linux/taskstats.h b/include/uapi/linux/taskstats.h
index 736154171489..a7f5b11a8f1b 100644
--- a/include/uapi/linux/taskstats.h
+++ b/include/uapi/linux/taskstats.h
@@ -34,7 +34,7 @@
  */
 
 
-#define TASKSTATS_VERSION	12
+#define TASKSTATS_VERSION	13
 #define TS_COMM_LEN		32	/* should be >= TASK_COMM_LEN
 					 * in linux/sched.h */
 
@@ -194,6 +194,10 @@ struct taskstats {
 	__u64   ac_exe_dev;     /* program binary device ID */
 	__u64   ac_exe_inode;   /* program binary inode number */
 	/* v12 end */
+
+	/* v13: Delay waiting for write-protect copy */
+	__u64    wpcopy_count;
+	__u64    wpcopy_delay_total;
 };